Roofing elements made of bitumen-impregnated cellulose fibers have been known for many years and they serve to cover the roofs of buildings in a manner that is simple and inexpensive. These elements are relatively rigid and the deformations they can accept without risk of cracking, tearing, or breaking are of relatively limited amplitude. With elements that are large corrugated sheets, that does not present a problem since they are designed to be placed on flat slopes. However, some such roofing elements, in particular ridge tiles and hip tiles, are designed to cover particular zones of the roof that have shapes that are not plane. Such ridge or hip tiles are elongate one-piece elements in the form of an upside-down central gutter between two lateral plane flanges, the flanges being arranged on either side.
Along the edges of a roof, and in particular along the ridge line, the angle between the two slopes on either side of the edge may vary from one building to another. In order to provide effective rain-proofing and insulation, covering elements and in particular their side flanges need to be applied relatively accurately on the roof and its adjacent/underlying roofing element. If attempts are made to deform the roofing elements considerably so that it is properly applied against the roofing, there is a high risk of cracking, breaking, tearing, or fissuring either immediately or later on. Such faults generally appear along the top of the ridge tile and along the lines connecting the central gutter to the lateral flanges.
Thus, document US 2011/0151170 discloses shingle plane roofing plates both for the slope and for the ridge of a roof, which plates are based on a bitumen-covered mat of fibers. Cuts that are continuous and cuts that are discontinuous in the form of dotted or dashed lines are made in the plates so as to enable them to be separated into a plurality of portions. The plates may be placed on the ridge of the roof by being folded, without the conditions necessary for doing so and the consequences of doing so being specified.
With ridge tiles, it is therefore necessary to make different kinds of ridge tile that differ from one another by the internal angle between the flanges of the tile when it is not subjected to deformation. The internal angle between the flanges of the tile corresponds to the downwardly facing internal angle along the line of intersection between the two planes for carrying the lateral flanges of the tile, which flange must be applied against the roof and/or the underlying roofing elements already placed on the roof.
This leads to increased fabrication and storage costs and to a risk of error when installing the roofing elements if the kind of tile is not appropriate for the roof.
Devices are known that are for placing on the ridge of a roof and that are made of other materials, and in particular out of metals. By way of example, document GB 2 138 050 describes a ridge-covering system that is made up of two covering elements, an internal element having plane lateral flanges and an external element that is placed on the internal elements. Those elements are made of metals. Transverse ribs 7 are made on the internal element by stamping the metal. The lateral flanges are connected to the central portion of the internal element along an angled connection line. The angle of the lateral flanges of the internal element relative to the horizontal is 30 degrees outwards. Finally, the internal element is pierced through the thicknesses of its central portion for ventilation purposes. Document WO 2006/108231 describes a terminal element for a roof ridge. That element has front and lateral plane flanges that are pivotable about a rounded central portion in order to match the angles of different roofs. The lateral flanges are connected to the central element along respective connection lines and via respective pivot hinges enabling the flanges to be pivoted. In a variant (FIG. 7), the pivot is replaced by an angular fold line (712, 716) of the terminal element. Nevertheless, those documents relate to roofing elements made of materials other than those of the molded roof tiles made of bitumen-impregnated cellulose of the invention and they therefore give no information about the behavior of such roof tiles and their potential for being adapted. Furthermore, they are structures of different shapes and in particular they have angular connection lines between their various portions.
The Applicant has found that in spite of the relative rigidity of molded roofing elements made of bitumen-impregnated cellulose, the amplitude through which it is possible for the element to deform under stress without risk of it being deteriorated or destroyed can be greatly increased by giving the roofing element a shape of a particular type. Such deterioration or destruction corresponds to the appearance of cracks, tears, or breaks in the short or medium term. Generally, the behavior under stress is determined under determined experimental conditions, in particular climatic cycling in which temperature and moisture are varied.
For a roof tile, making an element with a particularly closed internal angle between the flanges enables the elements to be used over a wide range of roof ridge angles, which is not possible with conventional ridge tiles in which the internal angle between the flanges is much wider open. In addition, the particular shapes of the various portions of the element can also assist in improving the performance of the element in terms of adaptability.